knowing when to break up

I've been with my partner for 18 months. He's much younger than I am but we are both well into adulthood. In addition to the age gap, he identifies as bi which is totally fine. I have two kids from a marriage. It sounds like a lot, I know. For the most part, we get along great. Have similar interests and are mutually supportive. The problem is that we can't go a couple weeks without him being mad at me for something. It ranges from him feeling neglected to jelousy to me being five minutes late. It's draining. Part of me thinks he's not reached true maturity yet and the fact that he doesn't have kids, he doesn't understand how attentive you need to be to them. So my question is, do I stay and try to make it work (I'm on a tighter biological timeline than him) or gently let go of something not meant for me.